TeX Quellcode:

\begin{array}{rcrcrcrcrl} \text{I} & 4x &+& 5y &-& 8z &=& 21 \cr \cr & 4x &+& 5\left(-\dfrac{13}{11}+\dfrac{20}{11}z\right) &-& 8z &=& 21 \cr \cr &4x &-& \dfrac{65}{11}+\dfrac{100}{11}z &-& 8z &=& 21 & \vert &+\dfrac{65}{11} \cr \cr & 4x & & &+& \dfrac{12}{11}z &=& 21+\dfrac{65}{11} & \vert & -\dfrac{12}{11}z \cr \cr & 4x& & & & &=& \dfrac{296}{11}-\dfrac{12}{11}z & \vert & :4 \cr \cr & & & & & x &=& \dfrac{74}{11}-\dfrac{3}{11}z & \end{array}